The present invention relates to an image forming apparatus which is capable of executing events, such as xe2x80x9cauto power offxe2x80x9d, xe2x80x9cauto power savexe2x80x9d, xe2x80x9cautomatic image quality maintenance adjustmentxe2x80x9d, etc., and which is exemplified by a digital copying machine.
In the conventional art, an image forming apparatus is known which can save standby power by its functions of xe2x80x9cauto power offxe2x80x9d, xe2x80x9cauto power savexe2x80x9d, etc. The auto power off function is a function of automatically turning off the power supply to the entire copying machine if no operation is performed during a preset length of time from the end of the last printing operation. The auto power save function is a function of automatically switching the copying machine into a power save mode (in which the copying machine is kept in the standby state, with minimum power applied) if no operation is performed during a preset length of time from the end of the last printing operation. The power save mode is an operation mode in which the power supply to the heat rollers of a fixing unit and to a fan is cut off, or the power supplied to the fixing unit is kept at a reduced level. When a copy is made after using the auto power off function or the auto power save function, a startup operation (e.g., a warming-up operation) has to be executed until the temperature of the fixing unit reaches a predetermined value.
Some image forming apparatuses (e.g., copying machines) have the function of an image quality maintenance adjustment or an automatic alignment adjustment. The automatic image quality maintenance adjustment enables automatic adjustment of the settings required for maintaining a desirable quality. The automatic alignment adjustment enables automatic adjustment of the settings required for a print image to be borne on a predetermined position. The automatic image quality maintenance adjustment and the automatic alignment adjustment are made when a predetermined length of time has elapsed or when a preset number of copies have been made.
The image forming apparatuses provided with the functions of xe2x80x9cauto power offxe2x80x9d, xe2x80x9cauto power savexe2x80x9d, xe2x80x9cautomatic image quality maintenance adjustmentxe2x80x9d and xe2x80x9cautomatic alignment adjustmentxe2x80x9d, may have the following problems.
(1) Let us assume that a user intends to use a copying machine and is making preparations for documents to be copied in the neighborhood of the main body of the copying machine. If, in this situation, the auto power off function works, the user has to turn on the power supply to the main body and wait for the startup operation (e.g., a warming-up operation) to come to an end before the start of the copying operation. In this manner, if the auto power off function works and the main power supply of the copying machine is turned off when the user is near the main body of the copying machine, the user has to turn on the power supply and wait for the startup operation to come to an end before the start of the copying operation.
(2) As in the case (1) above, let us assume that a user intends to use a copying machine and is making preparations for documents to be copied in the neighborhood of the main body of the copying machine. If, in this situation, the auto power save function works, the user has to cancel the power save mode by operating the related key, and wait for the startup operation (e.g., a warming-up operation) to come to an end before the start of the copying operation. In this manner, if the auto power save function works and the copying machine is switched into the power save mode, the user has to operate the power save mode-canceling key and wait for the startup operation to come to an end before the start of the copying operation.
(3) Let us assume that the automatic image quality maintenance adjustment is unexpectedly made when the user is making a copy of a plural-page document. In this case, the copying operation is interrupted, and the user has to wait for the image quality maintenance adjustment to come to an end. Unless this adjustment comes to an end, the copying operation cannot be resumed. For this reason, a long time is required for completing the copying operation. In addition, the image quality of prints may vary before and after the image quality-adjusting operation. If the image quality markedly varies as a result of the image quality maintenance adjustment, it may happen that a copying operation for the plural-page document has to be executed again from the beginning.
(4) As in case (3) above, let us assume that the automatic alignment adjustment is unexpectedly made when the user is making a copy of a plural-page document. In this case, the copying operation is interrupted, and the user has to wait for the automatic alignment adjustment to come to an end. Unless this adjustment comes to an end, the copying operation cannot be resumed. For this reason, a long time is required for completing the copying operation. In addition, if the print position may greatly vary before and after the alignment adjustment, a copying operation for the plural-page document may have to be executed again from the beginning.
The present invention is intended to solve the problem that when a preset length of time has elapsed, a variety of events may unexpectedly occur, resulting in extra labor and time before the start of image formation. Accordingly, an object of the present invention is to provide an image forming apparatus which prevents various events from undesirably starting on the basis of their preset times, and which therefore does not require extra labor or time before the start of image formation.
The present invention is also intended to solve the problem that unexpected occurrence of various events during image formation lengthens the time needed before the completion of the image formation, and also the problem that the image formation results may vary before and after the occurrence of an event. Accordingly, another object of the present invention is to provide an image forming apparatus which prevents unexpected occurrence of various events when image formation is being executed, thereby obviating extra time before the completion of the image formation, and which prevents image formation results from varying before and after the occurrence of an event, thereby allowing the image forming results to be as faithful possible to the user""s intention.
An image forming apparatus according to the present invention is provided with an operation section with which a user enters designations, and an image formation section for forming an image on an image formation medium, and comprises: a memory to store a first period of time and a second period of time, the first period of time being defined between a point of time when a standby state, where the image formation section is ready to form an image is switched on and a point of time when an event is started, the second period of time being defined between the point of time when the standby state is switched on and the start of an advance notice of the execution of the event; a timer to measure a length of time starting from the point of time when the standby state is switched on; a display device to display a period of time left before the start of the event, when the length of time measured by the timer indicates the elapse of the second period of time and keep operating until the event is started; and a control section to reset the period of time measured by the timer, with the standby state maintained, when a designation is entered from the operation section in the state where the display device is displaying the period of time left before the start of the event, and to start the event when the first period of time has elapsed without no designation being entered from the operation section.
Another image forming apparatus according to the present invention is provided with an operation section with which a user enters designations, and an image formation section for forming an image on an image formation medium, and comprises: a memory to store a first period of time and a second period of time, the first period of time being defined between the end of a last event and the start of a next event, the second period of time being defined between the end of the last event and the start of a notice of the next event; a timer to measure a length of time starting from the end of the last event; a display device to display a period of time left before the start of the event, the display device being designed to start operating when the length of time measured by the timer indicates the elapse of the second period of time and keep operating until the event is started; and a control section to control a subsequently scheduled event to be executed after the end of image formation which is then being executed by the image formation section, when a cancel command for canceling the subsequently-scheduled event is entered from the operation section in the state where the display device is displaying the period of time left before the start of the event.
Still another image forming apparatus according to the present invention is provided with an operation section with which a user enters designations, and an image formation section for forming an image on an image formation medium, and comprises: a memory to store a first value and a second value, the first value representing the number of image formation mediums on which the image formation section forms an image between the point of time when a last event is executed and the point of time when a next event is started, the second value representing the number of image formation mediums on which the image formation section forms an image between the point of time when the last event is executed and the point of time when a notice of the next event is issued; a counter to count the number of image formation mediums on which the image formation section forms an image after the end of the last event; a display device to display the number of image formation mediums left unprocessed before the start of the next event, when the number of image formation mediums counted by the counter has reached the second value and keep operating until the next event is started; and a control section to control a subsequently-scheduled event to be executed after the end of image formation which is then being executed by the image formation section, when a cancel command for canceling the subsequently-scheduled event is entered form the operation section in the state where the display device is displaying the number of image formation-mediums left unprocessed before the start of the next event.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.